From: WTShaw on
Indirect keys in Cryptography can generate even lengthy or complex
direct keys, those used in actual encryption whereas remembering them
would be difficult.

I often use Words to help generate Permutations which are used as
direct keys. Classically, a word or a few at most would be used as a
key but since all was done by hand, it could not be complicated, key
or algorithm.

With computer techniques, binary keys are often used as direct keys in
binary based algorithms. Some added means of saving such keys is
essential. Imagine my laughter when someone wrote me on sci.crypt that
I was making things too easy.

Indirect Keys made with my methods have the advantage and the
potential to make keys that meet the criteria of any algorithm even as
permutations are my thing.